The present invention relates to an integrated circuit test interface system, and more specifically to a test apparatus having a socket guide plate that aligns the integrated circuit being tested to conductive flexible elements integrated into a laminated printed circuit board.
In the past, contactors have been used to electrically connect the individual leads of a semiconductor package with a test apparatus to electrically test the component. Some semiconductor packages are peripherally leaded which have leads joining the package body around the outside edge of the package. Peripherally leaded packages include quad-flat, small outline, plastic leaded chip carrier, dual in-line and molded carrier rings among others. Peripherally leaded packages come in various dimensions and leads may be positioned around all four sides of the package or around less than all sides.
Previous apparatuses used to make electrical test connection to peripherally leaded packages and other types of semiconductor packages have severe limitations for high performance devices as well as reliability issues for operation when used with high volume, automated device handling equipment. Many of the problems result in poor electrical performance. Typically, this is due to long electrical path lengths within the contactor. Long electrical path lengths exhibit undesirable impedance effects which interfere with the integrity of the electrical tests being performed on the device under test. Undesirable impedance effects include long paths of uncontrolled impedance. Such uncontrolled impedance paths distort high frequency signal integrity and allow cross-talk between physically adjacent paths. Other undesirable impedance effects include parasitic inductance, capacitance, and resistance. Parasitic path inductance interferes with device power and ground sourcing by inducing voltage spikes during instantaneous electrical current changes. Parasitic capacitance presents undesirable electrical loading of the device and test electronic signal sources. Parasitic resistance causes voltage errors when significant current must flow through the resistive path. This is only a partial list of undesirable impedance effects which occur with long electrical paths in test contactors.
Previous test contactors often performed poorly in high volume test environments which employ automated device handling equipment. Contactor fragility often results in contactor damage when a handling equipment error presents a device to a contactor incorrectly. Contactors often wear rapidly during high volume use resulting in wear damage to alignment features and contact surfaces. Contactors may also be too susceptible to contamination from normal production environment debris such as package resin dust and package lead solder-plating.
Consequently there is a need for a contactor that is quick and simple to manufacture and eliminates electrical performance problems of undesirable impedance effects.